Expansion is only 581.70 MB.

That's only for the English version, however, with other localisations being slated for a release sometime in July.

Microsoft paid big bucks for 30 day exclusivity on the first two chunks of Skyrim downloadable content, meaning PS3 and PC gamers will have to wait.

The pack promises to add over 20 hours of content and will set you back 1600 MS Points. For your 581.70 MB download you're getting new weapons, abilities, quests and, if you choose, the chance to become a vampire lord.

"The 1600 Microsoft Point asking price for Dawnguard certainly looks a bit steep, but if Bethesda isn't telling porkies with the amount of content you're getting it could be a real highlight this summer," Martin wrote in our Dawnguard preview from E3 2012.